A conventionally-known so-called autonomous traveling type vacuum cleaner (cleaning robot), for example, cleans a cleaning target surface while traveling autonomously on the cleaning target surface and detecting an obstacle or the like by using a sensor and the like. Such a vacuum cleaner includes a body case with a dust collecting part, and the like. A dust collecting port communicating with the dust collecting part is formed in a lower part of the body case. A pair of drive wheels to make the body case travel autonomously is attached to the lower part of the body case. The body case is provided with the dust collecting part. For cleaning, dust and dirt is fed to the dust collecting part through the dust collecting port with an electric blower housed in the body case or a rotary brush arranged at the dust collecting port.
In this vacuum cleaner, the positioning of the drive wheels on both sides of the dust collecting port make it impossible to broaden the dust collecting port in a direction toward both sides. Thus, for cleaning of a place beyond the reach of the dust collecting port such as one near a wall, for example, side brushes with which dust and dirt is to be swept up and collected into the dust collecting port are provided on both sides of the lower part of the body case and ahead of the drive wheels. In this structure, making the side brushes project as much as possible from the body case expands a cleanable area. However, if the side brushes project excessively from the body case, the side brushes may get snagged on an obstacle and the like while the body case is traveling and cause a risk of interfering with the travel. Thus, it is preferable that the side brushes project from the body case but retreat immediately when the side brushes contact an obstacle.